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This invention relates to crosslinked organic particles and suspensions thereof, and to methods for preparing crosslinked organic particles and their suspensions. More particularly, the invention relates to crosslinked organic particles that exhibit a very good affinity for organic oils such as mineral oils and synthetic oils, and that also exhibit suitable affinity for silicone oils. The invention additionally relates to very efficient methods for preparing crosslinked organic particles. Further, the invention relates to crosslinked organic particle suspensions that have excellent handling properties, and which are highly blendable with other components. The invention also relates to very efficient methods for preparing the suspensions.
Silicone rubber particles have excellent resistance to heat, cold, and weathering, and have excellent electrical properties. As a consequence, they are useful as impact resistance improvers, flexibilizers, cracking inhibitors, flatting agents, softeners, tactile sensation improvers, oil absorbents, and lubricants for thermoplastic resins, thermosetting resins, paints, coatings, cosmetics, rubbers, and toners and carriers for electrostatic development.
However, while silicone rubber particles have a very good affinity for silicone oils, they suffer from a poor affinity for organic oils such as mineral oils and synthetic oils.
To address such problems, Japanese Laid Open (Kokai or Unexamined) Patent Application Number Hei 9-3408 (3,408/1997) discloses silicone rubber particles that contain C5 to C30 alkyl groups bonded to the silicon therein. These silicone rubber particles nevertheless remain a problem because their affinity for organic oils does not reach an acceptable level, yet their affinity for silicone oils is still high.
It is an object of the invention, therefore, to provide crosslinked organic particles that exhibit a very good affinity for organic oils such as mineral oils and synthetic oils, and that also exhibit a suitable affinity for silicone oils.
Another object is to provide highly efficient methods for preparing crosslinked organic particles.
An additional object is to provide crosslinked organic particle suspensions that have excellent handling properties, and which are highly blendable with other components.
Yet another object is to provide highly efficient methods for preparing such suspensions.
These and other features of the invention will become apparent from a consideration of the detailed description.
Not applicable.
Crosslinked organic particles according to the invention have an average particle size of 0.1 to 500 xcexcm, and are provided by the hydrosilylation-induced crosslinking of a fluid composition comprising (A) an organic compound that has at least 2 aliphatically unsaturated bonds in each molecule, (B) an organopolysiloxane that has at least 1 alkenyl group in each molecule, (C) a silicon-containing organic compound that has at least 2 silicon-bonded hydrogen atoms in each molecule, and (D) a catalyst of the hydrosilylation reaction.
Crosslinked organic particle containing suspensions of the invention contain water, an emulsifying agent, crosslinked organic particles, and wherein the particles are dispersed in water.
One method for preparing crosslinked organic particles is to emulsify a fluid composition comprising (A) an organic compound that has at least 2 aliphatically unsaturated bonds in each molecule, (B) an organopolysiloxane that has at least 1 alkenyl group in each molecule, (C) a silicon-containing organic compound that has at least 2 silicon-bonded hydrogen atoms in each molecule, and (D) a catalyst of the hydrosilylation reaction, in water using an emulsifying agent, crosslinking the fluid composition by carrying out an hydrosilylation reaction, and thereafter removing the water.
Another method for preparing crosslinked organic particles is to emulsify a fluid composition comprising components (A), (B), and (C), in water using an emulsifying agent, thereafter adding component (D), then crosslinking the composition by carrying out hydrosilylation, and finally removing water.
One method for preparing suspensions of crosslinked organic particles according to the invention is by emulsifying a fluid composition comprising (A) an organic compound that has at least 2 aliphatically unsaturated bonds in each molecule, (B) an organopolysiloxane that has at least 1 alkenyl group in each molecule, (C) a silicon-containing organic compound that has at least 2 silicon-bonded hydrogen atoms in each molecule, and (D) a catalyst for the hydrosilylation reaction, in water using an emulsifying agent, and crosslinking the fluid composition by carrying out the hydrosilylation reaction.
Another method for preparing suspensions of crosslinked organic particles is by emulsifying a fluid composition comprising components (A), (B), and (C), in water using an emulsifying agent, thereafter adding component (D), and then crosslinking the composition by carrying out hydrosilylation.
Crosslinked organic particles of the invention are crosslinked organic particles provided as a result of an hydrosilylation-induced crosslinking of the fluid composition of components (A) through (D) described above. These particles should have an average particle size in the range from 0.1 to 500 xcexcm, and preferably they have an average particle size in the range from 0.1 to 200 xcexcm. It is quite difficult to prepare crosslinked organic particles with an average particle size below the lower limit of the given range. Crosslinked organic particles with an average particle size exceeding the upper limit of the given range exhibit an increasingly impaired dispersibility, when blended into organic resins, paints, coatings, and cosmetics. The shape of the crosslinked organic particles can be spherical, spindle-shaped, plate-like, disk-like, or irregular, with a spherical shape being preferred. The crosslinked organic particles can be elastomeric in form such as a soft gel or rubber, or they can be a hard resin. Elastomers such as gels and rubbers are preferred, and rubbers are particularly preferred.
Organic compound (A) contains at least 2 aliphatically unsaturated bonds in each molecule. The aliphatically unsaturated group in (A) can be a group present in a molecular chain terminal position or in a pendant position on the molecular chain. It can be an alkenyl group such as vinyl, allyl, butenyl, and pentenyl; an alkynyl group such as ethynyl; or a cyclic unsaturated group such as the norbornene group or dicyclopentadienyl. The aliphatically unsaturated group can also be within the molecular chain, in which case, it would constitute an enylene group such as vinylene or propenylene. Groups present in the terminal or pendant position on the molecular chain such as vinyl and allyl are preferred, however.
Component (A) can be a solid or liquid, but liquids are preferred. When component (A) is a solid, it is necessary to preliminarily dissolve it in component (B) or (C), or component (A) can be dissolved in an organic solvent. While the molecular weight of component (A) is not critical, its average molecular weight is preferably in the range from 50 to 50,000.
Component (A) can be exemplified by dienes such as pentadiene, hexadiene, heptadiene, octadiene, nonadiene, cyclopentadiene, and cyclooctadiene; aromatic dienes such as divinylbenzene; ethers such as diallyl ether, triethylene glycol divinyl ether, cyclohexane dimethanol divinyl ether, and 1,2-divinylglycol; diene esters such as diallyl isophthalate, diallyl phthalate, diallyl terephthalate, diallyl maleate, and triallyl trimellitate; oligomers from polymerization of any of the former; olefin oligomers containing at least 2 aliphatically unsaturated bond-containing groups in each molecule which are produced by polymerization of an olefin such as ethylene, propylene, butene, isobutene, pentene, or hexene; oligomers from polymerization of an alkenyl-functional acrylic monomer such as allyl (meth)acrylate, butenyl (meth)acrylate, methylbutenyl (meth)acrylate, methylpropenyl (meth)acrylate, heptenyl (meth)acrylate, and hexenyl (meth)acrylate; oligomers from copolymerization of acrylic monomer listed above with a monomer such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate, styrene, xcex1-methylstyrene, maleic acid, vinyl acetate, or allyl acetate; oligomers from the reaction of an alkenyl isocyanate such as allyl isocyanate, (meth)acryloyl isocyanate, or 2-isocyanatoethyl (meth)acrylate), or an alkenyl-functional carboxylic acid anhydride such as itaconic anhydride, maleic anhydride, or tetrahydrophthalic anhydride, with an oligomer produced by copolymerization of monomers referenced above and a hydroxyl-functional acrylic monomer such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or 4-hydroxybutyl (meth)acrylate; oligomers from the reaction of an alkenyl alcohol such as allyl alcohol, butenol, 2-(allyloxy)ethanol, glycerol diallyl ether, cyclohexene methanol, methylbutenol, and oleyl alcohol, with an oligomer produced by polymerization of an isocyanate-functional acrylic monomer such as (meth)acryloyl isocyanate and 2-isocyanatoethyl (meth)acrylate) or with oligomers produced by copolymerization of such isocyanate-functional acrylic monomers with monomers referenced above; oligomers from reaction of an alkenyl-functional epoxy compound such as glycidyl (meth)acrylate and allyl glycidyl ether with an oligomer produced by polymerization of a carboxyl-functional monomer such as (meth)acrylic acid, itaconic acid, and maleic acid, or with an oligomer produced by copolymerization of such carboxyl-functional monomers with monomers referenced above; polyethers obtained by ring-opening polymerization of allyl glycidyl ether using ethylene glycol as the initiator; polyethers obtained by the ring-opening polymerization of vinylcyclohexane-1,2-epoxide using butanol, allyl alcohol, or propargyl alcohol as the initiator; alkenyl-functional polyesters from the reaction of an alkenyl alcohol such as referenced above, a polyhydric alcohol such as ethylene glycol, propylene glycol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, the neopentyl glycol ester of hydroxypivalic acid, and trimethylolpropane, and a polybasic acid such as phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, azelaic acid, and trimellitic acid. Component (A) is preferably a diene, diene oligomer, or polyether.
Organopolysiloxane (B) must contain at least 1 alkenyl group in each molecule, but preferably contains at least 2 alkenyl groups in each molecule. The alkenyl group in (B) can be exemplified by vinyl, allyl, butenyl, and pentenyl, with vinyl being preferred. The non-alkenyl Si-bonded groups in (B) can be exemplified by monovalent hydrocarbon groups. Representative groups which can be used include alkyl groups such as methyl, ethyl, propyl, and butyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl, tolyl, and xylyl; aralkyl groups such as benzyl, phenethyl, and 3-phenylpropyl; and halogenated hydrocarbyl groups such as 3-chloropropyl and 3,3,3-trifluoropropyl. The molecular structure of component (B) can be straight chain, branched chain, cyclic, network, or partially branched straight chain, but straight-chain molecular structures are preferred. The viscosity of (B) at 25xc2x0 C. is preferably from 20 to 100,000 mPaxc2x7s, and particularly preferably is from 20 to 10,000 mPaxc2x7s.
Component (B) can be exemplified by trimethylsiloxy-endblocked dimethylsiloxane-methylvinylsiloxane copolymers; trimethylsiloxy-endblocked methylvinylpolysiloxanes; trimethylsiloxy-endblocked dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers; dimethylvinylsiloxy-endblocked dimethylpolysiloxanes; dimethylvinylsiloxy-endblocked methylvinylpolysiloxanes; dimethylvinylsiloxy-endblocked dimethylsiloxane-methylvinylsiloxane copolymers; dimethylvinylsiloxy-endblocked dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers; organopolysiloxane copolymers containing R3SiO1/2, R2R1SiO1/2, and SiO4/2 siloxane units; organopolysiloxane copolymers containing R2R1SiO1/2 and SiO4/2 siloxane units; organopolysiloxane copolymers containing RR1SiO2/2 siloxane units and RSiO3/2 or R1SiO3/2 siloxane units; and mixtures of two or more of such organopolysiloxanes.
The R group in these units represent non-alkenyl monovalent hydrocarbyl groups among which are included alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; and halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl. The R1 group in the units represents an alkenyl group such as vinyl, allyl, butenyl, pentenyl, hexenyl, or heptenyl.
The content of (B) in the composition preferably is such as to provide a component (A):component (B) weight ratio in the range from 0.1:99.9 to 99.9:0.1, more preferably in the range from 0.5:99.5 to 50:50. A content of component (B) above the upper limit of the range causes an increasingly diminished affinity for organic oils by the crosslinked organic particles. A content below the lower limit of the range causes an increasingly diminished affinity for silicone oils by the crosslinked organic particles.
Silicon-containing organic compound (C) contains at least two silicon-bonded hydrogen atoms in each molecule. Component (C) preferably has a viscosity at 25xc2x0 C. in the range from 1 to 100,000 mPaxc2x7s, and particularly preferably in the range from 1 to 10,000 mPaxc2x7s. The silicon-containing organic compound (C) can be exemplified by organohydrogenpolysiloxanes, and by organic polymers that contain diorganohydrogensilyl groups, with organohydrogenpolysiloxanes being preferred.
Organohydrogenpolysiloxanes encompassed by component (C) can have a straight-chain, branched-chain, cyclic, network, or partially branched straight-chain molecular structure, and can be exemplified by trimethylsiloxy-endblocked methylhydrogenpolysiloxanes; trimethylsiloxy-endblocked dimethylsiloxane-methylhydrogensiloxane copolymers; trimethylsiloxy-endblocked dimethylsiloxane-methylhydrogensiloxane-methylphenylsiloxane copolymers; dimethylhydrogensiloxy-endblocked dimethylpolysiloxanes; dimethylhydrogensiloxy-endblocked dimethylsiloxane-methylphenylsiloxane copolymers; dimethylhydrogensiloxy-endblocked methylphenylpolysiloxanes; organopolysiloxane copolymers containing R3SiO1/2, R2HSiO1/2, and SiO4/2 siloxane units; organopolysiloxane copolymers containing R2HSiO1/2 and SiO4/2 siloxane units; organopolysiloxane copolymers containing RHSiO2/2 siloxane units and RSiO3/2 or HSiO3/2 siloxane units; and mixtures of two or more of such organopolysiloxanes. The group R in these units represents a non-alkenyl monovalent hydrocarbyl group, and it is the same as the groups referenced above.
Diorganohydrogensilyl-functional organic polymers encompassed by component (C) can be exemplified by oligomers from copolymerization of dimethylhydrogensilyl-functional acrylic monomers such as dimethylhydrogensilyl (meth)acrylate and dimethylhydrogensilylpropyl (meth)acrylate with monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate, styrene, xcex1-methylstyrene, maleic acid, vinyl acetate, and allyl acetate.
The content of component (C) in the composition provides preferably from 0.5 to 500 weight parts (C), and particularly preferably from 1 to 100 weight parts (C), in each case, for each 100 weight parts of the total amount of components (A) and (B). The possibility of an inadequate crosslinking arises when the content of component (C) in the composition falls below the lower limit of the range. A composition in which the content of component (C) exceeds the upper limit of the range risks evolution of hydrogen gas due to an excess of silicon-bonded hydrogen.
Component (D) is a catalyst for hydrosilylation reactions and one which promotes the hydrosilylation reaction in the composition, thereby inducing the crosslinking thereof. Component (D) can be exemplified by platinum catalysts, rhodium catalysts, and palladium catalysts, with platinum catalysts being preferred. Platinum catalysts can be exemplified by Pt-on-finely divided silica, Pt-on-finely divided carbon, chloroplatinic acid, alcohol solutions of chloroplatinic acid, olefin complexes of platinum, alkenylsiloxane complexes of platinum, and carbonyl complexes of platinum.
The content of component (D) in the composition is not critical, but component (D) should be added in a catalytic quantity sufficient to promote the hydrosilylation reaction in the composition. For a platinum catalyst as component (D), component (D) is preferably added in a quantity to provide from 1xc3x9710xe2x88x927 to 1xc3x9710xe2x88x923 weight parts of platinum metal for each 100 weight parts of the total amount of components (A), (B), and (C). Adequate crosslinking may not occur when the content of component (D) in the composition is below the lower limit of the range. The use of quantities in excess of the upper limit of the range is not particularly effective, and such quantities are uneconomical.
Optional components which can be added to the composition are exemplified by inhibitors for controlling the hydrosilylation reaction; reinforcing fillers such as precipitated silica, fumed silica, calcined silica, and fumed titanium oxide; semi-reinforcing fillers such as crushed quartz, diatomaceous earth, aluminosilicates, iron oxide, zinc oxide, and calcium carbonate; and any of such fillers after surface treatment with an organosilicon compound such as hexamethyldisilazane, trimethylchlorosilane, polydimethylsiloxane, or a polymethylhydrogensiloxane.
A noncrosslinking oil can also be admixed into the composition. The noncrosslinking oil can be a noncrosslinking silicone oil such as trimethylsiloxy-endblocked dimethylpolysiloxanes, trimethylsiloxy-endblocked methylphenylpolysiloxanes, trimethylsiloxy-endblocked dimethylsiloxane-methylphenylsiloxane copolymers, trimethylsiloxy-endblocked dimethylsiloxane-methyl(3,3,3-trifluoropropyl)siloxane copolymers, cyclic dimethylsiloxanes, and cyclic methylphenylsiloxanes. Noncrosslinking organic oils can also be used, representative of which are alkanes such as hexane and heptane; aromatic hydrocarbons such as benzene and toluene; chlorinated hydrocarbons such as carbon tetrachloride and methylene chloride; ketones such as methyl isobutyl ketone; alcohols such as undecyl alcohol; ethers such as dibutyl ether; esters such as isopropyl laurate and isopropyl palmitate, liquid paraffin, isoparaffin, hexyl laurate, isopropyl myristate, myristyl myristate, cetyl myristate, 2-octyldecyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, butyl stearate, decyl oleate, 2-octyldodecyl oleate, myristyl lactate, cetyl lactate, lanolin acetate, stearyl alcohol, cetostearyl alcohol, oleyl alcohol, avocado oil, almond oil, olive oil, cacao oil, jojoba oil, sesame oil, safflower oil, soy oil, camellia oil, squalane, persic oil, castor oil, mink oil, cottonseed oil, coconut oil, egg yolk oil, lard; glycol ester oils such as polypropylene glycol monooleate and neopentyl glycol 2-ethylhexanoate; polyhydric alcohol ester oils such as isostearate triglyceride and cocofatty acid triglycerides; and polyoxyalkylene ether oils such as polyoxyethylene lauryl ether and polyoxypropylene cetyl ether. The noncrosslinking oil preferably has a viscosity at 25xc2x0 C. in the range from 1 to 100,000,000 mPaxc2x7s, and particularly preferably in the range from 2 to 10,000,000 mPaxc2x7s. The noncrosslinking oil is preferably present in the composition in an amount to provide from 0.1 to 5,000 weight parts of the noncrosslinking oil for each 100 weight parts of the composition excluding the noncrosslinking oil.
Suspensions according to the invention contain the crosslinked organic particles described above, an emulsifying agent, and water, with the particles being dispersed in water. The emulsifying agent functions to improve the stability of the crosslinked organic particles in water. The emulsifying agent can be a cationic surfactant, an anionic surfactant, an amphoteric surfactant, a nonionic surfactant, or a mixture of any of such surfactants.
Cationic surfactants can be exemplified by the salts of primary, secondary, and tertiary amines, alkyltrimethyl ammonium salts, dialkyldimethyl ammonium salts, tetraalkyl ammonium salts, trialkylbenzyl ammonium salts, alkylpyridinium salts, N,N-dialkylmorpholinium salts, and salts of polyethylene polyamine aliphatic amides.
Anionic surfactants can be exemplified by the salts of aliphatic acids, the salts of alkylbenzene sulfonic acids, the salts of alkylnaphthalene sulfonic acids, the salts of alkylsulfonic acids, the salts of a-olefin sulfonic acids, the salts of dialkyl sulfosuccinates, xcex1-sulfonated aliphatic acid salts, N-acyl-N-methyltaurates, alkyl sulfate salts, sulfated oils, polyoxyethylene alkyl ether sulfate salts, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styrenated phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylphenyl ether phosphates, and formaldehyde condensates of naphthalene sulfonates.
Amphoteric surfactants can be exemplified by N,N-dimethyl-N-alkyl-N-carboxymethyl ammonium betaines, N,N-dialkylaminoalkylene carboxylates, N,N,N-trialkyl-N-sulfoalkylene ammonium betaines, N,N-dialkyl-N,N-bispolyoxyethylene ammonium sulfate ester betaines, and 2-alkyl-1-carboxymethyl-1-hydroxyethyl imidazolinium betaines.
Nonionic surfactants can be exemplified by polyoxyethylene alkyl ethers, polyoxyethylene alkenyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyrylphenyl ethers, polyoxyethylene-polyoxypropylene glycols, and polyoxyethylene-polyoxypropylene alkyl ethers; aliphatic acid partial esters of polyhydric alcohols such as aliphatic acid esters of sorbitan, aliphatic acid esters of glycerol, aliphatic acid esters of decaglycerol, aliphatic acid esters of polyglycerol, aliphatic acid esters of ethylene glycol/pentaerythritol, and aliphatic acid esters of propylene glycol/pentaerythritol; polyoxyethylene adducts of aliphatic acid partial esters of polyhydric alcohols such as polyoxyethylene adducts of aliphatic acid esters of sorbitan and polyoxyethylene adducts of aliphatic acid esters of glycerol; polyoxyethylene/aliphatic acid esters; aliphatic acid esters of polyglycerol; polyoxyethylated castor oil; diethanolamides of aliphatic acids; polyoxyethylene alkylamines; aliphatic acid partial esters of triethanolamine; trialkylamine oxides; and polyoxyalkylene-functional organopolysiloxanes. Nonionic surfactants are preferred, however.
The content of the emulsifying agent is preferably from 0.1 to 20 weight parts, and particularly preferably from 0.5 to 10 weight parts, in each case, for each 100 weight parts of the crosslinked organic particles. While the amount of water is not critical, it should preferably constitute from 5 to 99 weight % of the suspension, more preferably from 10 to 80 weight %.
The suspensions may contain other ingredients representative of which are additives for stabilizing the dispersion or adjusting the viscosity including ethanol and water-soluble polymers such as xanthan gum, guar gum, carboxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, carboxyvinyl polymers, hydroxyethylcellulose, and polyoxyethylene glycol distearate; film-forming agents such as polymers of radically polymerizable (meth)acrylic monomers, copolymers of silicone compounds with radically polymerizable (meth)acrylic monomers, poly(N-acylalkylene imine)s, poly(N-methylpyrrolidone)s, and silicone resins containing fluorinated organic groups, amino groups, or silanol groups; oxidation inhibitors such as BHA, BHT, and xcex3-orizanol; antifreezes such as ethanol, isopropyl alcohol, 1,3-butylene glycol, ethylene glycol, propylene glycol, and glycerol; antimicrobials and preservatives such as triclosan and triclocarban; pearlescent agents; chelating agents such as ethylenediamine tetraacetic acid, citric acid, ethane-1-hydroxy-1,1-diphosphonic acid, and their salts; UV absorbers including benzophenone derivatives such as 2-hydroxy-4-methoxybenzophenone, benzotriazole derivatives such as 2-(2xe2x80x2-hydroxy-5xe2x80x2-methylphenyl) benzotriazole, and cinnamic acid esters; colorants such as chromatogens, dyes, and pigments; spray-enabling agents; vitamins; hair tonics; growth promoters; hormones; fragrances; and perfumes.
Crosslinked organic particles and suspensions containing the particles are useful as components for imparting properties such as lubricity, softness, and flexibility to lubricants, cleaning agents, flatting agents, cosmetics, and materials employed in electrostatic development such as toners and carriers; as components for imparting properties such as flatness, softness, and flexibility to paints and coatings; and as components for imparting properties such as lubricity and impact resistance to thermosetting resins and thermoplastic resins.
One method for preparing the suspension is by emulsifying a fluid composition containing components (A), (B), (C), and (D), in water using an emulsifying agent, and then crosslinking the composition by effecting hydrosilylation.
Another method for preparing the suspension is by emulsifying a fluid composition containing components (A), (B), and (C), in water using an emulsifying agent, adding component (D), and subsequently crosslinking the composition by effecting hydrosilylation.
Components (A), (B), (C), and (D) used in these methods are the same as the components described above. The emulsifying device used during the emulsifying agent-supported emulsification of the component (A)-(D) composition in water, during the emulsifying agent-supported emulsification of the component (A)-(C) composition in water, and during the addition of component (D) to the component (A)-(C) composition, can be exemplified by homomixers, paddle mixers, Henschel mixers, homodispersers, colloid mills, propeller-type stirrers, homogenizers, inline continuous emulsifiers, ultrasound emulsifiers, and vacuum mills.
Surfactants of the type described above can be used as the emulsifying agent in these methods, and the use of a nonionic surfactant is particularly preferred. The emulsifying agent is preferably added at from 0.1 to 20 weight parts, and particularly preferably at from 0.5 to 10 weight parts, in each case, for each 100 weight parts of the total amount of components (A) to (D). The amount of water addition is not critical, but it preferably constitutes from 5 to 99 weight % of the overall emulsion, and more preferably 10 to 80 weight %.
The suspension of the crosslinked organic particles can be produced by heating the emulsion of the fluid composition, or by holding the emulsion at room temperature to effect hydrosilylation-induced crosslinking of the water-dispersed fluid composition.
Crosslinked organic particles for use herein should have an average particle size in the range from 0.1 to 500 xcexcm, and preferably have an average particle size in the range from 0.1 to 200 xcexcm. It is quite difficult to prepare crosslinked organic particles with an average particle size below the lower limit of the range. Crosslinked organic particles with an average particle size exceeding the upper limit of the range exhibit an increasingly impaired dispersibility when blended into organic resins, paints, coatings, and cosmetics.
The shape of the crosslinked organic particles can be spherical, spindle-shaped, plate-like, disk-like, or irregular, with a spherical shape being preferred. They can be in the form of an elastomer such as a soft gel or rubber, or they can be in the form of a hard resin. Elastomers such as gels and rubbers are preferred, and rubbers are particularly preferred.
The technique used in the methods to remove water from the suspension containing the particles is exemplified by spraying the suspension into a hot gas current, freeze-drying the suspension, or addition of salt to the suspension to aggregate the crosslinked organic particles, followed by thermal drying of the separated slurry of the crosslinked organic particles. It is preferred that the crosslinked organic particles be used in the form of a suspension, since suspensions offers particularly good handling characteristics, and are blendable with other components.